A motor 10 includes: a yoke on whose inner surface a four-pole magnet is attached; a gear case 15 jointed to an opening portion of the yoke and storing a speed-reduction mechanism; a brush holder 30 stored in an opening portion 15a of the gear case and having a through hole 31 penetrated by a commutator 23 attached to an armature shaft 21 in a center of the brush holder; and a first brush 36, a second brush 35, and a third brush 37 which are stored so as to freely come in and out to/from three brush storing portions 32, 33, and 34 formed so as to interpose the through hole 31 in the brush holder 30. In the motor, the second brush 35 is arranged at a position shifted from the first brush 36 in a rotational direction by 90 degrees, and a third brush 37 is arranged within an included angle opposite to an included angle formed by the first brush 36 and the second brush 35.